CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
OPERATING ACTIVITIES:
Net income	$ 85,385	$ 45,222	$ 54,070
Adjustments to reconcile net income to net cash provided from operating activities:
Depreciation	13,464	9,957	8,064
Deferred income and expense, net of amortization	(1,323)	(1,534)	1,541
Amortization of core deposit intangibles	7,061	3,164	1,990
Loss (gain) on sale of securities, net	(843)	540	(42)
Net change in valuation of financial instruments carried at fair value	2,620	813	(1,374)
Purchases of securities—trading	(1,725)	(6,338)	(2,387)
Proceeds from sales of securities—trading	7,839	4,419	2,387
Principal repayments and maturities of securities—trading	3,746	9,535	27,709
Bargain purchase gain on acquisition	0	0	(9,079)
(Increase) decrease in deferred taxes	7,883	(3,906)	2,966
(Decrease) increase in current taxes payable	(2,184)	(1,519)	11,771
Equity-based compensation	3,435	3,486	2,269
Increase in cash surrender value of BOLI	(4,507)	(2,481)	(1,788)
Gain on sale of loans, net of capitalized servicing rights	(17,713)	(10,716)	(6,080)
Gain on disposal of real estate held for sale and property and equipment	(1,389)	(391)	(1,076)
PROVISION FOR LOAN LOSSES	6,030	0	0
Provision for real estate held for sale	876	216	36
Origination of loans held for sale	(1,063,328)	(709,035)	(361,859)
Proceeds from sales of loans held for sale	880,890	677,166	367,888
Net change in:
Other assets	3,759	(7,319)	(2,310)
Other liabilities	(6,664)	4,090	3,370
Net cash (used by) provided from operating activities	(76,688)	15,369	98,066
INVESTING ACTIVITIES:
Purchases of securities—available-for-sale	(243,115)	(141,989)	(58,705)
Principal repayments and maturities of securities—available-for-sale	191,534	113,431	62,520
Proceeds from sales of securities—available-for-sale	369,755	232,620	56,267
Purchases of securities—held-to-maturity	(60,344)	(13,357)	(38,961)
Principal repayments and maturities of securities—held-to-maturity	11,009	12,978	9,194
Loan originations, net of repayments	(46,042)	(32,675)	(144,152)
Purchases of loans and participating interest in loans	(314,301)	(323,533)	(194,381)
Proceeds from sales of other loans	233,419	124,407	11,277
Net cash received from acquisitions, net of branch divestitures	0	24,208	127,557
Proceeds from Sale of Property, Plant, and Equipment	14,513	4,740	4,923
Purchases of property and equipment	(16,239)	(12,072)	(5,935)
Proceeds from FHLB stock repurchase program	80,681	48,843	8,354
Purchase of FHLB stock	(77,130)	(23,634)	0
Other	2,707	1,092	(2,025)
Net cash provided from (used by) investing activities	146,447	15,059	(164,067)
FINANCING ACTIVITIES:
Increase in deposits, net	66,346	226,821	68,938
Repayment of long term FHLB borrowing	(95,009)	(8)	(8)
Advances, net of (repayments) of overnight and short-term FHLB borrowings	16,400	(120,400)	5,000
Increase (decrease) in other borrowings, net	7,360	16,140	(5,871)
Cash dividends paid	(28,282)	(17,170)	(13,462)
Cash proceeds from issuance of shares for shareholder reinvestment plan	0	34	127
Cash paid for repurchase of common stock	(50,772)	0	0
Net cash (used by) provided from financing activities	(83,957)	105,417	54,724
NET CHANGE IN CASH AND CASH EQUIVALENTS	(14,198)	135,845	(11,277)
CASH AND CASH EQUIVALENTS, BEGINNING OF YEAR	261,917	126,072	137,349
CASH AND CASH EQUIVALENTS, END OF YEAR	247,719	261,917	126,072
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Interest paid in cash	16,722	12,252	10,929
Taxes paid in cash	36,153	27,256	13,047
NON-CASH INVESTING AND FINANCING TRANSACTIONS:
Loans, net of discounts, specific loss allowances and unearned income, transferred to real estate owned and other repossessed assets	9,146	4,456	3,493
Dividends accrued but not paid until after period end	7,662	6,271	3,570
ACQUISITIONS (Note 3):
Assets acquired	0	4,829,748	221,206
Liabilities assumed	$ 0	$ 4,249,751	$ 212,127